<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<script>
			var s='nihao';
			s=s.concat('js');
			alert(s);
			s="This is a dog";
			var p1=s.indexOf("is");
			alert(p1);
			var p2=s.indexOf("is",4);
			alert(p2);
		</script>
	</head>
	<body>
	</body>
</html>
